This invention relates to cutting tools and more particularly a rotary blade that cuts and sands materials at the same time.
Conventional rotary saw blades used to cut wood and other materials actually tear or rip through the materials leaving small splinters attached to the edge of the cut. Accordingly, a worker has to perform additional work to remove such splinters by sanding or filing the edges of the cut. Notwithstanding such sanding or filing, when two pieces of the cut material are abutted, such as in molding, trim and miter joints, the unsightly cut lines can be easily seen, even after the joint is stained or painted.
Thus, there exists a need for a cutting tool that will create a smooth cut and also reduce the labor associated with trying to smooth the cut.
Some prior inventions have attempted to fulfill the above need, but none is like the present invention. The most pertinent prior art includes the following U.S. Patents:
The Lloyd-Young teaches a circular saw blade with sand paper removably attached to one side by rivets through slots in the blade. The two Smith patents teach circular saw blades with sandpaper fixed to both sides but the sand paper is not removable. Also, either Smith patent does not teach the use of pieces of abrasive material extending wavily from the center of the blade as does one embodiment of the present invention. The use of pieces of abrasive material reduces drag on the blade requiring less horse power to rotate the blade and eliminates a wood burn due to heating on the blade on the surfaces covered by abrasive material. The two Schweickhardt patents cover an apparatus and method involving a saw blade with diamond abrasive on the sides for dry cutting masonry and concrete. The Highberg, et al. patent discloses a cylindrical milling tool that has abrasive inserts on it. The Larish patent teaches a combination joint and sanding machine that has circular cutting blades with a sanding surface on one side of the blade. The Kucharczyk teaches a drill press which has cutter inserts for planing and an abrasive disk for finishing. The Nitz, et al. patent discloses oscillating cutting blades with grips on the edges for smoothing cuts. The Green patent teaches a jigsaw blade with rasp sides to smooth cuts for painting. Russian Patent No. 1,722,822 shows a disc saw with ring bands of abrasive material, an arrangement which would not provide a uniform smooth cut. The Murata patent discloses a cutting blade with abrasive material in recesses, but it is not a rotary blade as is the present invention. The Weiss shows a cutting blade with abrasive particles bonded only to the inner cutting edge. The Bley patent also shows a blade with abrasive material on the cutting edge. Finally, Cunningham shows a grinding wheel with abrasive material on the grounding surfaces thereof.
Unlike the present invention, none of the prior art discloses cutting and sanding blades having the same structure as the present invention or blades that have a plurality of removable abrasive pads which may be replaced when worn or as desired without having to remove the rotary blade from a power saw.
The major objects of the present invention are to provide a cutting tool which:
Makes a smooth cut in wood, plastic, metal or other material;
Reduces the time and costs of labor assisted with cutting materials;
Performs the cutting and sanding job without additional power requirements;
Allows the abrasive sanding surface to be changed when worn or as desired; and
Allows a multiplicity of different abrasive surfaces to be used so that the cut is gradually sanded and polished.
The present invention accomplishes the above and other objects by affixing abrasive sanding means to a conventional rotary saw blade positionally so it does not cover the cutting teeth and is outward of the central access hole of the cutting blade. The abrasive sanding means extends beyond each face of the blade a sufficient amount so as to shear off slivers of material that normally remain after cutting, which have to be sanded and polished along the cut line made in the materials. The abrasive sanding means may consist of two sheets of material, one each on each face of the blade or may consist of a plurality of abrasive sanding pieces that are distributed around the blades so the full sanding coverage is made during the cut. The abrasive sanding means may be adhesively attached to the blades so that they can be removed and replaced when worn or as desired. Although the combined width of the abrasive sanding means and rotary saw is designed to be approximately equal to the kerf of the blade so as not to require additional electrical horsepower requirements for the power saw, a saw blade with recessed areas is also provided so that thick abrasive surfaces may be utilized and not extend beyond the kerf of a blade.